Immunogenetic studies of two recently contacted populations from Papua New Guinea

We have examined the HLA profiles of the Hagahai and the Haruai people, two linguistic groups in the remote western Schrader mountains who have only recently had administrative contact, and compared them with those of other populations in Papua New Guinea. None of the antigens detected in the two groups was found missing in other populations although significant differences in allele frequencies exist. Recent contact history does not appear to have played any significant role in shaping these differences. Similarly, no evidence of differential selection pressures contributing to HLA heterogeneity was found. The genetic profiles of the Hagahai and the Haruai appear to be a result of recent admixture between unrelated, genetically disparate groups.     

Identifying subgroup markers in heterogeneous populations

Traditional methods that aim to identify biomarkers that distinguish between two groups, like Significance Analysis of Microarrays or the t-test, perform optimally when such biomarkers show homogeneous behavior within each group and differential behavior between the groups. However, in many applications, this is not the case. Instead, a subgroup of samples in one group shows differential behavior with respect to all other samples. To successfully detect markers showing such imbalanced patterns of differential signal, a different approach is required. We propose a novel method, specifically designed for the Detection of Imbalanced Differential Signal (DIDS). We use an artificial dataset and a human breast cancer dataset to measure its performance and compare it with three traditional methods and four approaches that take imbalanced signal into account. Supported by extensive experimental results, we show that DIDS outperforms all other approaches in terms of power and positive predictive value. In a mouse breast cancer dataset, DIDS is the only approach that detects a functionally validated marker of chemotherapy resistance. DIDS can be applied to any continuous value data, including gene expression data, and in any context where imbalanced differential signal is manifested.     

Biochemical gene markers in Komy populations

Gene pool of two Komy groups and Komy-Permiakh group has been characterized for biochemical gene markers Hp, Tf, Gc, C'3, PGM1, EsD, AcP, GLO1. Genetical characteristics of the groups investigated, other Finnish-Ugorh peoples and those neighbouring Komy peoples of no Finnish-Ugorh origin are compared. Genetical position of Komy peoples in the system of peoples of the Euro-Asia has been defined.     

Paternally inherited markers in bovine hybrid populations

The genetic integrity of crossfertile bovine- or cattle-like species may be endangered by species hybridization. Previously, amplified fragment length polymorphism, satellite fragment length polymorphism and microsatellite assays have been used to analyze the species composition of nuclear DNA in taurine cattle, zebu, banteng and bison populations, while mitochondrial DNA reveals the origin of the maternal lineages. Here, we describe species-specific markers of the paternally transmitted Y-chromosome for the direct detection of male-mediated introgression. Convenient PCR-restriction fragment length polymorphism and competitive PCR assays are shown to differentiate the Y-chromosomes of taurine cattle, American bison and European bison, and to detect the banteng origin of Indonesian Madura and Bali cattle bulls.     

Comparison of erythrocyte markers gene frequencies in different populations

A comparison of erythrocyte markers (ABO, Rh system) gene frequencies was done by bar code diagrams in populations of variable ethnic origin. The results from missions for the development in Far East Asia (China, Indochina, New Guinea) were compared to well known gene frequencies of the populations living in other regions: inhabitants of the islands of the Pacific ocean, Europeans of New Zealand and Western Europe (France), Europeans of North America, Ameridans of Peru and Bolivia, Somalians of Africa. Polymorphism was observed in immense country very peopled, monomorphism was found in small and isolated region but polymorphism existed in tribes living in very isolated islands.     

Immunogenetic polymorphism of lipoproteins in swine

Five new antigenic markers (allotypes) of swine serum lipoproteins are described. Specific antiallotype reagents were obtained from alloimmune precipitating sera. Identification studies and genetic analysis indicate that the five serum alloantigens—designated Lpp6, Lpp11, Lpp12, Lpp13, and Lpp14—are markers of low-density lipoproteins (LDL),d 1.002–1.075 g/ml, and are members of a previously described Lpp system. The Lpp6 allotype belongs to the group of individual markers and is determined by a new codominant allelic gene,Lpp ⁶, whereas the remaining four antigens—Lpp11, Lpp12, Lpp13, and Lpp 14—named common specificities, behave as alternative variants to Lpp1, Lpp2, Lpp3, and Lpp4, respectively, forming pairs of mutually exclusive alloantigens. Each Lpp gene in a heterozygous animal expresses itself independently on separate molecules and each haplotype carries one individual and at least four common specificities. The relationship between common and individual specificities, together with their number in the complex haplotypes, seems to shed some light on evolution of Lpp genes. It is proposed in this concept that the original gene for low-density lipoproteins in swine, and also in rhesus monkeys and the human, consisted of genetic information for common specificities only, the individual specificities evolving later as a result of point mutations.     

Classifying genealogical origins in hybrid populations using dominant markers

In hybrid studies, potential for error is high when classifying genealogical origins of individuals (e.g., parental, F1, F2) based on their genotypic arrays. For codominant markers, previous researchers have considered the probability of misclassification by genotypic inspection and proposed alternative maximum-likelihood approaches to estimating genealogical class frequencies. Recently developed dominant marker systems may significantly increase the number of diagnostic loci available for hybrid studies. I examine probabilities of classification error based on the number of dominant loci. As in earlier studies, I assume that only parental and first- and second-generation hybrid crosses between two taxa potentially exist. Thirteen loci with dominant expression from each parental taxon (i.e., 26 total loci) are needed to reduce classification error below 5% for F2 individuals, compared to 13 codominant loci for the same error rate. Use of loci in similar numbers from both taxa most efficiently increases power to characterize all genealogical classes. In contrast, classification of backcrosses to one parental taxon is wholly dependent on loci from the other taxon. Use of dominant diagnostic markers may increase the power and expand the use of maximum-likelihood methods for evaluating hybrid mixtures.     

Microsatellite markers for the study of cetacean populations

Microsatellites are one of the most important classes of nuclear genetic markers and offer many advantages for the study of marine mammals. Here we describe the isolation and characterization of 12 cetacean microsatellites which are then tested across 30 different cetacean species. For around half the species tested, five or more polymorphic loci were identified. Since many species were represented by only one or two specimens, this figure is likely to underestimate the usefulness of these markers. No relationship was found between microsatellite repeat length and proportion of species which gave polymorphic products.     

Analysis of genetic recombination in maize populations using molecular markers

Summary Variation in recombination rate is important to plant breeders since a major objective is to obtain favorable recombinants of linked genes. The ability to increase recombination (R) in circumstances in which favorable and unvavorable genes are linked (Corn Belt x exotic populations) and to decrease recombination when many favorable genes are linked (narrow-based, elite populations) would be of immense value. However, the concept of variation in recombination frequencies between linked genes has received limited attention despite its implications in breeding and genetic linkage studies. Molecular techniques have allowed better estimations of this variation. In this study, attempts were made to characterize: (1) the R values in the Pgm1-Adh1 and Adh1-Phi1 adjacent regions of chromosome 1 and the Idh2-Mdh2 region of chromosome 6 in F₂ families of three maize (Zea mays L.) populations; (2) the environmental effect on R values of F₂s from two populations. One population, NSO, was a Corn Belt synthetic, and the other two populations, CBMEX3 and CBCAR5, were composites from crosses between Corn Belt and exotic germ-plams.Wide ranges of estimated recombination ( ) values were observed among families in each population for all three chromsomal regions. The distribution of values for the Pgm1-Adh1 region showed that the F₂ families of each population fell into two broad categories: 0.30–0.50 and 0.02–0.20. No intermediates (0.21–0.29) were found. The distributions were almost normal for the Adh1-Phi1 and the Idh2-Mdh2 regions. It would appear that the major dispersion in the Pgm1-Adh1 region was controlled by the effects of a single gene, while the Adh1-Phi1 and Idh2-Mdh2 regions were only affected by polygenes. No correlation was found between recombination values of the two adjacent regions, indicating that the genes affecting recombination for the Pgm1-Adh1 region may be specific for that region.For the Pgm1-Adh1 region, no differences in values were found among the three populations. For the Adh1-Phi1 region, frequencies of CBMEX3 and NSO were not significantly different, but both had significantly greater values than CBCAR5. For the Idh2-Mdh2 region, CBMEX3 was significantly different from NSO. There were significant differences between some paired F₂ families within each population for each chromosome region.No significant differences in response to the two environments were detected in CBMEX3 and NSO for either region in chromosome 1.Published as Journal Paper No. 9498 of the Nebraska Agric Res Div, University of Nebraska, Lincoln, Neb. Research supported in part by USDA Competitive Grant 87-CRCR-2359     

Genetic markers and psoriasis in three ethnic populations of Dagestan

Analysis of clinical material obtained from the individuals (49 psoriasis patients and 357 individuals without this disease) representing three ethnic populations of Dagestan (Avars, Dargins, and Kumyks) was performed. Polymorphism of the blood group loci AB0, Rhesus (RH), Kell, P, and Lewis, as well as of the protein-encoding loci for haptoglobin (HP), group-specific component (GC), and the enzymes, including glycosylase (GL01), esterase D (ESD), 6-phosphate dehydrogenase (6PDG), and acid phosphatase (ACP), was studied. It was demonstrated that in the pooled sample of Avars and Kumyks the Lewis system phenotype Le(a-b-) and the RH homozygotes (ee/ee) were statistically significantly more frequent among the psoriasis patients (P = 0.0488 and P = 0.0166, respectively), than among healthy controls of the same ethnic groups. It was suggested that for the pooled sample of Avars and Kumyks, homozygosity for the recessive RH allele (ee/ee) in combination with the Le(a-b-) phenotype, representing homozygosity for recessive allele le, was the risk factor for the development of psoriasis.     

Planktonic Fauna of Small Reservoirs in the Komi Republic

One hundred and eight species and forms of planktonic organisms have been revealed in three small reservoirs in the Komi Republic (the northeast of European Russia). Species that were not previously known for the water bodies of the Vychegda River Basin (Limnosida frontosa) and the Republic of Komi (Lecane mira, Macrochaetus subquadratus, Filinia longiseta limnetica, and Rhynchotalona falcata) have been found. It has been established that the richness of the planktonic fauna depends on the age of the water body: the maximum number of species is found in the oldest reservoir, namely, the Kazhim Reservoir. The planktonic communities of artificial reservoirs are distinguished by a low level of similarity of faunas both with each other and in comparison with the natural lakes of the region. The fauna distribution in the old reservoirs is uneven. The relatively large fauna richness of planktonic communities in the littoral zones is due to the water-level regime in the reservoirs.     

Immunogenetic studies of rhesus monkeys

To assay for transplacental immunization in rhesus monkeys, sera from 253 postpartum females, 31 virgin females, and 40 males were tested for erythrocyte agglutinins. Nineteen percent of the mothers exhibited antibodies, but less than three percent of the virgin females or males did so. Antibodies were detected in 26 percent of the mothers who bore blood group-incompatible infants, in contrast to only eight percent of the mothers with compatible offspring. Thus, blood group incompatibility may lead to transplacental alloimmunization of the rhesus female. Unlike the situation in humans, hemolytic disease was not observed, even when the erythrocytes of the newborn rhesus were coated with maternal antibodies.     

Immunogenetic studies of rhesus monkeys

Five alloimmune rhesus monkey blood typing reagents have been produced which define two new blood group loci inMacaca mulatto. Three of these reagents detect blood group factors at theM locus; the other two detect factors at theN locus. By typing over 1900 pedigreed monkeys we have established that these two loci are independent of each other and of any of our previously defined blood group systems.     

Immunogenetic studies of rhesus monkeys

Five alloimmune blood typing reagents have been produced which define five new blood group systems in rhesus monkeys. Each of the five independent blood group loci is comprised of a detectable allele and a null allele. Using these new reagents and those previously described, we can potentially identify close to a million phenotypes in rhesus monkeys.     

Immunogenetic study of porcine IgG

Three allotypes of IgG were identified in pig. Based on data obtained on electrophoretic mobility as well as on results of the International Comparative Test ISABR for pig blood group, polymorphic proteins and enzymes (1987-1988), the allotypes are specified as markers of two different IgG subclasses and are referred to as IgG1a, IgG2b and IgG2c. The former of these is established as corresponding to the already known IGH3 C1, and the other two had not been earlier described. In herds of pigs being bred in the Georgian SSR, the IgG1a allotype frequencies in Kakhetinskaya, Large White, Landrase and Lithuanian white were 0.84, 0.93, 0.91 and 0.94, respectively, whereas for the IgG2b allotype it ran 0.89, 0.73, 0.79, and 0.69 in the order mentioned. The IgG2c allotype was not registered in samples under examination.